Disclaimer: This contains spoilers!

This past weekend all I've been seeing pop up is #HappyBirthdayHarryPotter. Harry Potter has been around for 19 years, just turning 36 on July 31st. Of course, the only true way to celebrate is for a Freeform Harry Potter weekend! And, being the Harry Potter fan that I am, I watched the movies. And when I watched the movies again, I realized a few things.

1. The actors grew up so much.

You don't really realize until you've watched all the movies how much the actors grew up in the process. These movies were not only their claim to fame, but their lives. From the release of the first to the last movie, a total of 10 years was spent on the series.

2. Technology advanced a lot.

Just look at the difference in the ghosts. The top photo shows Nearly Headless Nick in "Sorcerer's Stone," and the bottom shows Helena Ravenclaw in "Deathly Hallows Part 2." Notice how Helena looks more life like, like she's standing right there, whereas Nick looks more transparent.

3. Voldemort doesn't actually appear until the fourth movie.

Sure, Voldemort is seen briefly in "Sorcerer's Stone," but he's only really brought back in the "Goblet of Fire" in the Graveyard. It's only then when he says that he can actually touch Harry Potter again.

4. Rowling had the whole series planned out from the beginning.

In "The Chamber of Secrets," Harry kills the basilisk with the sword of Gryffindor, then proceeds to destroy Tom Riddle's diary with a basilisk fang. It's later revealed in "Half-Blood Prince" that the diary was a horcrux. Then in "Deathly Hallows Part 1," it's shared that the sword of Gryffindor can destroy horcruxes because it has basilisk venom within it (it takes in that which makes it stronger). This made me realize that JK probably had every little detail about the series planned before writing.

5. The books are worth the read

After all, they're why the movies were created. In the books, there's more detail and the books are flat out good. Yes, they're long, but you'll appreciate the movies much more!

6. Some of the characters completely change in the last one.

For one thing, Neville becomes confident. He stands up to Voldemort, saying how he'll never know love or friendship, and eventually killed Nagini, the last Horcrux. Then, McGonagell calls Filch a "blithering idiot." And, Molly Weasley defends Ginny in front of Bellatrix, saying "not my daughter, you bitch," right before killing her. It blew me away to see transformations from a shy Neville, a usually strict McGonagall, and an uptight Mrs. Weasley!

7. Some secondary characters have weird story lines.

Remember Colin Creevey and Justin Flynn-Fletchly from "The Chamber of Secrets"? Remember how you only see them in that movie and then they disappear? Or remember Fleur and how Ron tried to ask her to the Yule Ball? Then she isn't in "Order of the Phoenix" or "Half- Blood Prince," but then she reappears and is suddenly getting married to Bill, Ron's brother. Isn't that a little awkward for Ron to be dealing with?

8. Dumbledore's got style.

I'm pretty convinced Dumbledore is all-knowing. First, in "Sorcerer's Stone," he gives Harry his father's old invisibility cloak, the only instructions are to: "use it well." Then, Harry ends up needing it to get to the stone. Then, in "Chamber of Secrets" when Harry and Ron are at Hogwarts with the cloak, Dumbledore says "help will always be given at Hogwarts" and looks right at Harry and Ron. In the "Deathly Hallows Part 1," he also leaves the deluminator to Ron, who later says he thinks Dumbledore must have known he would lose his way and need it eventually. He also left "The Tales of the Beetle and the Bard" to Hermonie, who found a Deathly Hallows symbol, sparking their quest to discover the meaning of it. Plus, he tried to give Harry the sword of Gryffindor as he knew it could destroy horcruxes.

9. Snape is the most complex character.

We're introduced to Snape, and instantly he's the bad guy. He's shown in a light that makes it look like he absolutely hates Harry and wants him to die. Yet, Dumbledore says many times that he trusts Snape. Yet, we also see that Snape is a Death Eater working for Voldemort. Then, he kills Dumbledore. It isn't until "Deathly Hallows Part 2" where it becomes clear that Snape was only trying to look out for Harry. Yes, he kind of hated Harry because he reminded him of James, who he loathed, but, he was only a Death Eater to know what Voldemort was up to, and stay ahead of him.

10. I miss Alan Rickman even more now than before.

Alan Rickman was such a talented actor. When re-watching all the movies, it breaks my heart to know that he is no longer with us, and he can no longer see how Harry Potter is still loved, and how far it has come. RIP Rickman, you will be missed.

11. Harry, Ron, and Hermione are friendship goals.

At first, Harry and Ron hate Hermione because they think she's a know-it-all, but after the troll gets let in the school, they go looking for her, and ultimately save her. After this moment, they become inseparable. Through every movie, they stick together. Even in "Order of the Phoenix," Hermione says to Harry, "we're in this together." Even in the end of "Half-Blood Prince," they all agree to not go to Hogwarts the next year so that they can all look for horcruxes together. Plus, Ginny and Harry end up getting married, and Ron and Hermione, so they all end up being related anyways. If that isn't friendship, I don't know what is.

12. I don't think Draco actually wanted to be a bad person.

In the first few films, I can't stand Malfoy, but then my feelings toward him began to change in "Half-Blood Prince." Yes, he is a Death Eater, but when he cursed Katie Bell, he felt terrible. Before Harry confronted him in the boy's bathroom, you could see he had a look of regret, like he was about to cry. Later in the movie, he is supposed to kill Dumbledore, but he can't bring himself to do it. Also, in "Deathly Hallows Part 1," Draco doesn't tell his family that he recognizes Harry when he comes to Malfoy manner. Later, Harry asks him why, but Draco doesn't respond.

13. The kids of Hogwarts are in danger, a lot.

From going into the Forbidden Forest to serve a detention, a car crash into the Whomping Willow, and a dangerous triwizard tournament maze, the students of Hogwarts act like being in danger is no big deal. They seem to narrowly escape their situation, but somehow danger seems to find them each year.

14. Why was Gilderoy Lockhart hired?

I get it, desperate times call for desperate measures, but Gilderoy Lockhart? He literally has no clue what he's doing. He was the reason Harry lost the bones in his arm after all. Luckily, the Defense Against the Dark Arts position is cursed. And by the way, did he ever gain his memory back?

15. So many people died.

First Quirell, then Cedric, Sirius, and Dumbledore. The killings don't stop. Then, in the "Deathly Hallows," so many characters die during the war Harry even says "I never asked for anyone to die for me."

16. Madam Pomfrey is a sass master.

Whenever someone has to go to the hospital, it's never a fun trip. But with Madame Pomfrey, she doesn't make it that much easier. When Harry loses his bones in "Chamber of Secrets," he goes to the hospital to get the bones regrown. When he takes a drink of the regrowth juice, he spits it out because it tastes nasty, to which Madame Pomfrey replies, "what did you expect, pumpkin juice?"

17. The HP fandom will never die.

After watching eight movies, it makes you realize that the fandom is still very much alive. Parodies have continually been made, like "Potter Puppet Pals" or "A Very Potter Musical." "Harry Potter and the Cursed Child" was just released, and people have been flocking to Barnes and Noble for a copy. On top of that, Freeform does frequent Harry Potter weekends. I'm willing to bet that when this generation starts having kids, lots of them will be named after Harry Potter characters, because the fandom will live on.

"Potter, it's good to see you again." -Minerva McGonagall